I initially set out to write this post because I was playing around with some reflection code and thought I found something interesting. Alas, that was definitely not the case. Instead, it was just a basic feature of Kotlin that I haven’t needed to use or focus on yet. Although this post didn’t turn out the way I wanted it to, I still think it is a nice little post to bring some clarity to this subject.
In Java, there is the concept of primitive types and their wrapped versions. Thanks to autoboxing and unboxing, types can be interchanged between their primitive and wrapped versions. In other words, in most situations, you can use a long instead of a Long or a Long instead of a long. If you didn’t notice where the capitals were in that last sentence, then I imagine it probably looked quite confusing. The wording in that sentence is also crucial. More specifically, the statement “in most situations.”